http://www.forddoctorsdts.com/quizzes/MechanicalAptitude.php

I'm sure this has been posted before, though not sure if it has been in this forum.
probably worthwhile to have the basics covered. This is a reasonable way to evaluate your understanding of the basics. (bonus points for finding the poorly phrased questions.)

We still probably need to have a primer on the "basics" of physics though. Too many seem to miss the simple ones. (like friction)

90%, sucks that they don't tell you what you missed. :(

they do..click the pause looking button in the lower left

Bah, missed my first question at #31 :(

And I got 37 wrong too.

88% here...

88% here... damn it... didnt spend enough time reading it properly.

68% for me..

No way I can pass. I will miss every electrical question. :rofl

No way I can pass. I will miss every electrical question. :rofl
They're really really basic...

They're really really basic...

I could ask you very basic questions about the procedures of roll-forming, manufacturing and braking sheet metal.

In that sense basic may not be so basic for you. Same here. I know nothing of electronics.;)

Somebody look up the thread in the track forum and tell me what I got... I don't remember and I'm not doing it again. :rofl

I could ask you very basic questions about the procedures of roll-forming, manufacturing and braking sheet metal.

In that sense basic may not be so basic for you. Same here. I know nothing of electronics.;)
oh, I'm no EE, believe me. ;)

It was just basic parallel and serial circuits. Beyond that I'm lost.

82% for me. Neat test.

Didn't their physics teachers tell them theres no such thing as deceleration?

94%
48 was lame because the difference in pressure in the cylinder vs the atmosphere is caused by the piston moving down. Both b and c could concievably be correct.

Somebody look up the thread in the track forum and tell me what I got... I don't remember and I'm not doing it again. :rofl

94%

It asked the same question over and over again....

Damn, we tied. I wanted to win. :shifty

88% and I forgot to look at missed questions.....oh well thats why my car is at Active Autowerke for service.....

72% :-(

Supercharger guys probably got #35 wrong :)


94%

76% thats bs that thats not passing

88% - but hey, I'm a chemical engineer.........

If its an consolation I am an idiot :)

If its an consolation I am an idiot :)
No. No consolation at all. I'm an idiot chemical engineer......:confused

72%. Electrical got me.

Damnz electrical was cakes. Though I do that sort of stuff - I's a nerdz!!!! All 3 of my mistakes were made on the pulleys :(

92 % did not check where I crapped, some of the questions got me thinking longer, I guess that it's where i messed up, specially the two fans, I answered opposite direction since these two fans are identical, so the blades of the second one are a mirror image from the first, so the rotation will be reverse, but in fact since the air will spin a bit it should hit the blades from the side making negligible force unless you flip the impeller on the shaft, then you'll get same direction rotation.
Smarter peeps go nowhere :(

gboezio - thinking of it too much - think of a pinwheel when you were a kid. If you blow in it and it spins clockwise, what would happen if you stuck a motor on it and spun it the opposite dir? The air that normally hits it face-on and spins it clockwise is now being expelled from behind the fan through the front - which, when it hits the same fan opposite it, will make it react like the pinwheel did originally... spinning the "opposite" direction of the powered fan.

Yeah, the correct answer (at least correct for them) is same direction, the other that got me is the gear/screw, seemed obvious but I missed it,

Yea it took me a sec for the gear screw. I just assumed it was standard threading - it was too hard to see :)

ouch 82%. I almost have my masters degree in electrical engineering. I honestly thought I'd do a lot better.

Thanks for the link, cool test!

70% is passing in the military, im sticking with that standard (for my self esteem)

96%. I disagree with 'their' fan answer...

96%. I disagree with 'their' fan answer...

:shifty Me too

http://img108.imageshack.us/img108/1234/testaj0.th.gif (http://img108.imageshack.us/my.php?image=testaj0.gif)

82 :(

im a noob.

96%. I disagree with 'their' fan answer...

two identical fans. so we can say that both spin clockwise if viewed from their "front" when pushing air forward. (we can choose, because they are the same, so its trivial. :shifty)

If we know that airflow over the fan blades goes "forward" when its spinning clockwise, it thus needs to go "backwards" when its spinning counterclockwise.

If the fans are facing each other, "forward" for one is "backwards" for the other with respect to airflow direction.

If fan1 is turned on, airflow is assumed to be "forward". "forward" through fan1 is "backwards" through fan2's blades.

Thus if fan 1 is spinning clockwise, then fan 2 is spinning counterclockwise... with respect to different orientations. Counterclockwise WRT to "forward" on a backwards fan is the other fan's clockwise. thus they spin the same direction.

74%
I'll stick to porn and soccer.

two identical fans. so we can say that both spin clockwise if viewed from their "front" when pushing air forward. (we can choose, because they are the same, so its trivial. :shifty)

If we know that airflow over the fan blades goes "forward" when its spinning clockwise, it thus needs to go "backwards" when its spinning counterclockwise.

If the fans are facing each other, "forward" for one is "backwards" for the other with respect to airflow direction.

If fan1 is turned on, airflow is assumed to be "forward". "forward" through fan1 is "backwards" through fan2's blades.

Thus if fan 1 is spinning clockwise, then fan 2 is spinning counterclockwise... with respect to different orientations. Counterclockwise WRT to "forward" on a backwards fan is the other fan's clockwise. thus they spin the same direction.

Yup. i screwed that one up too.

MilkT, I feel like we are sitting in a class we shouldn’t have enrolled in while the smart kids (///M3///M5, BMW Sob, and techno550) argue with the teacher about extra credit. I just want the bell to ring so we can goto lunch and smoke a joint!

*i do not condone the use of drugs

two identical fans. so we can say that both spin clockwise if viewed from their "front" when pushing air forward. (we can choose, because they are the same, so its trivial. :shifty)

If we know that airflow over the fan blades goes "forward" when its spinning clockwise, it thus needs to go "backwards" when its spinning counterclockwise.

If the fans are facing each other, "forward" for one is "backwards" for the other with respect to airflow direction.

If fan1 is turned on, airflow is assumed to be "forward". "forward" through fan1 is "backwards" through fan2's blades.

Thus if fan 1 is spinning clockwise, then fan 2 is spinning counterclockwise... with respect to different orientations. Counterclockwise WRT to "forward" on a backwards fan is the other fan's clockwise. thus they spin the same direction.

or post 26 :)

75% for the economist. Never took an engineering class in my life.

two identical fans. so we can say that both spin clockwise if viewed from their "front" when pushing air forward. (we can choose, because they are the same, so its trivial. :shifty)

If we know that airflow over the fan blades goes "forward" when its spinning clockwise, it thus needs to go "backwards" when its spinning counterclockwise.

If the fans are facing each other, "forward" for one is "backwards" for the other with respect to airflow direction.

If fan1 is turned on, airflow is assumed to be "forward". "forward" through fan1 is "backwards" through fan2's blades.

Thus if fan 1 is spinning clockwise, then fan 2 is spinning counterclockwise... with respect to different orientations. Counterclockwise WRT to "forward" on a backwards fan is the other fan's clockwise. thus they spin the same direction.

They should have clarified that in the question. It is all about your mental reference point based on their description of the situation. I was thinking, relative to each other, they spin opposite. My logic was correct, so that is what counts. :stickoutt

94 here

Some truly sh*tty wording in a few of the questions.

#41 - pressure on piston creates a force which causes the red piston to generate PRESSURE at its face, not force, considering they were asking for an answer in PSI.

Some of the questions made me want to ask them if they could be a bit more vague...

You guys haven't taken standardized tests lately have you? :)

#41 is somewhat vague yes but when you see the numbers they give you and their loose wording I immediately recognized what they wanted. I scored quite quite well on all standardized tests which are somewhat similar to this and you just need to look at whats given and what your options are and use best judgement. I've had some pretty messed up questions on SATs and stuff.

94 here

Some truly sh*tty wording in a few of the questions.

#41 - pressure on piston creates a force which causes the red piston to generate PRESSURE at its face, not force, considering they were asking for an answer in PSI.

Some of the questions made me want to ask them if they could be a bit more vague...

Basically every question was like this. They commonly used the word 'force' and meant 'mass'.

I didn't do all that well. :( I won't post my score.

Sent it to my dad, he got 94% and did it super fast. He has issue with #7.

Nik

You guys haven't taken standardized tests lately have you? :)

#41 is somewhat vague yes but when you see the numbers they give you and their loose wording I immediately recognized what they wanted. I scored quite quite well on all standardized tests which are somewhat similar to this and you just need to look at whats given and what your options are and use best judgement. I've had some pretty messed up questions on SATs and stuff.

+1 i once found an error on a state mandated 3rd grade english exam, while i was taking it, always been a great test taker just by evaluating not so much the question, but the answers given to the question...well for multiple choice stuff anyways, obviously...

+1 i once found an error on a state mandated 3rd grade english exam, while i was taking it, always been a great test taker just by evaluating not so much the question, but the answers given to the question...well for multiple choice stuff anyways, obviously...

3rd grade exam :confused you are joking right?

Damn. 94%.


Pulleys own me. :( I always forget the MA of pulley setups.

Good quiz, but fairly basic stuff.

You guys haven't taken standardized tests lately have you? :)

#41 is somewhat vague yes but when you see the numbers they give you and their loose wording I immediately recognized what they wanted. I scored quite quite well on all standardized tests which are somewhat similar to this and you just need to look at whats given and what your options are and use best judgement. I've had some pretty messed up questions on SATs and stuff.

I am old, and therefore have not taken any "standardized" tests in a very long time other than my PE licensing exam, and even that was 7-8 years ago.

So, no, I don't appreciate the inaccuracy and vague nature of some of the questions and the wording. If they are trying to test my aptitude, they better damn sure have their aptitude to a collective level that is greater than my own.

My high school Physics teacher used to get pissed at me for correcting his exam key as well...

:atom

I am as dum as it gets... I got 72%, the electrical part got me and the gear screw....:mad

I dont like smart guys.. (loading my 9mil..) :ar15firin

MilkT, I feel like we are sitting in a class we shouldn’t have enrolled in while the smart kid (5mall5nail5) argues with the teacher (techno550) about extra credit. I just want the bell to ring so we can goto lunch and smoke a joint!


:lol :lol3
I hear you there.
My high school days were wasted,
but its never too late to use our minds.
BTW, I fixed your quote.

Takes too long.

I would have taken the theory tests, but I was too busy fitting bicycle tires to my car to ensure the most efficient width for traction. ;-)

I would have taken the theory tests, but I was too busy fitting bicycle tires to my car to ensure the most efficient width for traction. ;-)

sorry kenny, snide comments won't alter the laws of physics. ;)

btw, physics isn't theory, its the mathematics of reality.

sorry kenny, snide comments won't alter the laws of physics. ;)

btw, physics isn't theory, its the mathematics of reality.
Ahh .. I begin to understand .. science explains everything that can be observed ... how awe inspiring!

sorry kenny, snide comments won't alter the laws of physics. ;)

btw, physics isn't theory, its the mathematics of reality.
if you put incorrect shit in your equation, you get shit out
there has already been proof tires do not act like a balloon with a load applied, your model sucks as much as your smugness

Ahh .. I begin to understand .. science explains everything that can be observed ... how awe inspiring!

observation without scientific understanding leads one to the wrong conclusions. casual observation is the worst.

we can *see* that the earth is flat, fixed, and that the heavens revolve around us. no? :stickoutt

Not enough science, and we end up with a lot of assumptions. like the relationship between surface area and friction. that can make for some amusing threads though, no? the clutch threads, brake threads, and tire threads. Somehow its *only* the tire threads that are still debated or "unresolved"...

Mike, I was just going to forget about it, but after all the references and comments I can't help wondering the details behind this tire issue. Are you saying that since coefficients of friction aren't area-based that wider tires aren't necessarily better? Is there already a thread in which I could discuss this with you? I ask because I disagree, but would be interested to civilly discuss the theory as you mentioned and find out what your argument is.

Rich air,
Austin

barely made 80....luckily I play as a mechanich only with my car, and not for a living

sorry kenny, snide comments won't alter the laws of physics. ;)

btw, physics isn't theory, its the mathematics of reality.

If you think the coefficient of friction is the only thing that matters for tire traction, then you have only a freshmen level of understanding of physics. Unfortunately for your theory, this is not an "ideal" world where we can consider ideal traction situations. We must also consider the secondary effects such: temperature of rubber, compound, heat dissipation, sidewall flex, rubber compression against asphalt, etc.

Physics does describe reality. However, your simplified model doesn't. I've read your posts over the past few days, but they are just as flawed as saying the Earth is round. Your friction/tire assumptions will lead the similar errors when choosing tires for maximum traction.

can i put this thread on my transcript?

Your friction/tire assumptions will lead the similar errors when choosing tires for maximum traction.

The idea is that traction graphed against tire width is not a linear function, it has a peak at the optimal and it falls off to EITHER side. That's the point most people have missed. It's not that wider isn't better in some cases, it's that there is an optimal width for a particular application, and wider is not always faster (even if wider is sometimes more grip or more percieved grip)

observation without scientific understanding leads one to the wrong conclusions. casual observation is the worst.

we can *see* that the earth is flat, fixed, and that the heavens revolve around us. no? :stickoutt

Not enough science, and we end up with a lot of assumptions. like the relationship between surface area and friction. that can make for some amusing threads though, no? the clutch threads, brake threads, and tire threads. Somehow its *only* the tire threads that are still debated or "unresolved"...

Mike,

I see you continuing to remark about friction and the relationship with surface area. I am not going to discuss any of the specific applications you are refering to, but please remember that all mathematical representations of "reality" that scientists and engineers use to "understand" things, are based on fundamental assumptions. Those assumptions serve to make the problems manageable, since if we tried to actually model the REALITY of a phenomenon, the UGLY REALITY of the problem would lead to unsolvable mathematics.

The friction that we all learn about as engineers, physicists, or whatever, is rigid body friction only. It completely neglects the fact that all things deform under load.

We had a guy in here the other day with a project he wanted help on. We asked him how stiff it needed to be (wanting to define requirements for his project). He said that in its design condition, he would prefer it not deflect "at all". He required a lesson in basic physics, since even the smallest load, coupled with the stiffest object possible, would result in "some" deflection.

So, I hear what you are saying about things, and will agree that you are technically correct, given a state of assumptions. However be careful making blanket statements which, in my opinion, and experience, can possibly get you into trouble where the "representation" of a problem, has assumed enough "ugly reality" out of the model, to make it not entirely accurate...

:eek: omg everyone get down!

if you put incorrect shit in your equation, you get shit out
there has already been proof tires do not act like a balloon with a load applied, your model sucks as much as your smugness

my model isn't a ballon. The question isn't surface area directly either. I've created another tire thread in the FI section to handle what this would otherwise turn into. The tire physics threads are much more involved than a balloon model, but the "width != grip" bit still applies.

Do we disagree on the lack of surface area playing a part in clutch physics? brake physics? Do we need threads for those as well?

Mike,

I see you continuing to remark about friction and the relationship with surface area. I am not going to discuss any of the specific applications you are refering to, but please remember that all mathematical representations of "reality" that scientists and engineers use to "understand" things, are based on fundamental assumptions. Those assumptions serve to make the problems manageable, since if we tried to actually model the REALITY of a phenomenon, the UGLY REALITY of the problem would lead to unsolvable mathematics.

The friction that we all learn about as engineers, physicists, or whatever, is rigid body friction only. It completely neglects the fact that all things deform under load.

We had a guy in here the other day with a project he wanted help on. We asked him how stiff it needed to be (wanting to define requirements for his project). He said that in its design condition, he would prefer it not deflect "at all". He required a lesson in basic physics, since even the smallest load, coupled with the stiffest object possible, would result in "some" deflection.

So, I hear what you are saying about things, and will agree that you are technically correct, given a state of assumptions. However be careful making blanket statements which, in my opinion, and experience, can possibly get you into trouble where the "representation" of a problem, has assumed enough "ugly reality" out of the model, to make it not entirely accurate...

The basic physics still applies. especially since we measure friction force and normal force, and use coeff of friction as a derived variable. The deformation under load, the shape of the interface, all moot in many cases. (back to clutches?)

My blanket statements are meant to "simplify" the problem. The tire physics thing has been debated on a number of levels here. Most go directly after "wider = more grip" and have no understanding of friction. thus the basic friction model is there to break that, just like the "drag a block of wood on the big side then on the narrow side with a fish scale" experiment we've all done in 5th grade physical science. its important to see that distinction and understand it. For as many things that point to "wider has more friction force" in the "observed" there are just as many that point the other way. If we are dragging a piece of furniture across carpet, "more area = less friction" ...

The big picture here is that it is NOT OK to take casual observations and try to apply them universally. Misunderstanding the basics causes a lot of problems.
The other day flipping through the channels there was a "cops" or "and they walked away" kind of crash show on. A stunt guy tried to jump a bunch of cars in a similarly old crappy car. Not enough speed and wrong trajectory, but the net result was the car nose diving into the cars being jumped. The announcer guy attributes it to the stunt man not accounting for the car being front engine and thus the added weight of the engine up there pulled the nose of the car to the ground. Thats not how gravity works, and that pissed me off, so I changed the channel.

Mike,

UNderstand that I am not trying to refute anything said on tires or clutches/brakes, nor am I necessarily saying that you are wrong, or that your logic is flawed in any case.

What I AM saying is that the "basic physics still applies" comment, can, if you are not extremely careful, bite you in the ass BIG TIME in application as an engineer. You are intelligent, experienced, and you appear to get your ducks in a row before taking a position, which is good. However you appear to be (assumed from picture thread) relatively young, and I am just saying to proceed with caution, as at some point, things might not work quite the way you expect.

I work a lot in ballistics and lightweight armor. I have seen things that don't make ANY sense from a physical perspective. I have seen rooms full of PhD subject matter experts in certain areas, acknowledge that the observed result changed, but the chemistry (or physics) did not support the change. Sometimes it just happens that way.

I call BS on those who say they got 96% on this test, while doing it without cheating in any way.

I call for any results to be backed up with several screeshots (untampered ones)

1/ A screenshot of the final results screen

2/ a screenshot or 2 of the question results part showing what you got right and what you got wrong

:)

I call BS on those who say they got 96% on this test, while doing it without cheating in any way.

I call for any results to be backed up with several screeshots (untampered ones)

1/ A screenshot of the final results screen

2/ a screenshot or 2 of the question results part showing what you got right and what you got wrong

:)

You are taking it to far..:eyecrazy this will be one of those things that God is the only witness... From my part I could've used the search tool and learn about parallel circuits but I didn't.

I bet you if anybody retakes the test will score over 95% if they were smart enough to see what they missed the first time.

guys, let me know when it's a good time to step out and get more popcorn :)

I call BS on those who say they got 96% on this test, while doing it without cheating in any way.

I call for any results to be backed up with several screeshots (untampered ones)

1/ A screenshot of the final results screen

2/ a screenshot or 2 of the question results part showing what you got right and what you got wrong

:)


I got the "missed one question" score the first time I took it(96% you say?). It's not exactly difficult subject material, and anybody that pays attention and has some basic background knowledge should score rather well. It seems most people are missing questions due to poor diction on the part of the test writers.

I'd be wary of dealing with a mechanical/aeronautical engineer who couldn't get a 90%+ on that test with relative ease...

Mike,

UNderstand that I am not trying to refute anything said on tires or clutches/brakes, nor am I necessarily saying that you are wrong, or that your logic is flawed in any case.
..

Steve I just wanted to be clear, are you saying that Mike is right and that his logic is flawless?

I call BS on those who say they got 96% on this test, while doing it without cheating in any way.

I call for any results to be backed up with several screeshots (untampered ones)

1/ A screenshot of the final results screen

2/ a screenshot or 2 of the question results part showing what you got right and what you got wrong

:)

I got a 98 wiht a screen shot in my original post, I didn't think it was really that crazy of a claim.

Realisticly, One could right down all the answers and get 100.... But where's the fun in that.

I got the fan one wrong, didn't like the relative wording.

Donovan

Steve I just wanted to be clear, are you saying that Mike is right and that his logic is flawless?

No I am not saying that.

I am making a point unrelated to the details of the whole contact patch, tire, blah blah thing, because I refuse to get involved in that discussion. Some people are always hell bent on having a physics and mathematics based explanation for everything. I am confident that that explanation does exist in some way shape or form, but for many things we observe as humans, we are quite far away from having the understanding to actually generate that explanation...

I'll take the battles one at a time.

Steve, how bout I take the tires out of the above statements on "the basic physics still applies" and leave it at brakes and clutches. that work for you? ;)

Hee hee, yeah, I can probably give you that one!


EDIT: And I am sure you are probably relieved! Now you can sleep at night...

:lol

90%

Mis-estimated the 2:1 gear ratio.... I counted 10 and 24 the first time :(

Could not muster the brain to figure the many pulley reduction

misread the planetary and balloon questions =/



I got a little captain in me!

:ausw_6

No I am not saying that.

I am making a point unrelated to the details of the whole contact patch, tire, blah blah thing, because I refuse to get involved in that discussion. Some people are always hell bent on having a physics and mathematics based explanation for everything. I am confident that that explanation does exist in some way shape or form, but for many things we observe as humans, we are quite far away from having the understanding to actually generate that explanation...
OK, understood. You're not saying Mike is wrong and you're not saying he is right, gotcha.

Is that you, John Kerry?

Sorry had to.

So wtf is the "truth"?


Continue.